In assembling CRT display devices, or any display devices utilizing electron guns, an important aspect is to provide the electron guns into the display device in an ultra clean condition. Particles that adhere to such electron guns, as well as oils and greases that appear during construction of the electron gun, must be removed in order to obtain and improve high voltage emission and CRT life performance. The ability to clean the electron guns from such various contaminants is an extremely necessary operation in order to reduce the number of rejects of such electron guns both in constructing display devices and resulting in subsequent customer problems.
Current CRT gun cleaning techniques typically use aqueous processes. This means that CRT guns are immersed in distilled water and agitated, or they are sprayed with distilled water, to remove particulate contamination. Many problems, however, arise when a water cleaning process is used to clean CRT electron guns. For example, aqueous cleaning of blind spots or holes and small crevices is very difficult. Further, aqueous processes require careful engineering and process control. Also, various residues are difficult to rinse from metal and/or synthetic resin surfaces of CRT guns.
The prior use of distilled water rinsing, or even an alcohol rinsing and cleaning technique, has resulted in many difficulties. For example, aqueous cleaning may require a significant amount of floor space in carrying out such cleaning. Further, drying CRT electron guns having complex geometry is difficult to accomplish quickly where crevices and blind holes occur. Moreover, CRT gun compatibility with water is poor since corrosion of metals or stress cracking of certain materials may occur. Finally, high purity water is necessary for CRT gun cleaning. High purity water can be very expensive depending on its purity and the volume used.